The answer would be the first choice :D
Chemicals can make mutations by a number of mechanisms. Base
analogs are incorporated into DNA and mostly pair with the wrong base.
Alkylating agents, deaminating chemicals, hydroxylamine, and oxidative radicals
change the structure of DNA bases, thus altering their pairing properties.
Introducing agents wedge between the bases and cause single-base insertions and
deletions in replication.
The correct answer is “B”
I hope this helps